This invention relates in general to vehicular brake systems, and in particular is concerned with control valves mounted in a hydraulic control unit of an electronically controlled brake system.
Electronically-controlled brake systems for vehicles are well known. One type of electronically-controlled brake system includes a hydraulic control unit (HCU) connected in fluid communication between a master cylinder and a plurality of wheel brakes. The HCU includes a housing containing control valves and other components for selectively controlling hydraulic brake pressure at the wheel brakes.
Control valves for HCU""s are commonly formed as electronically actuated solenoid valves. A typical solenoid valve includes a cylindrical armature slidably received in a sleeve or flux tube for movement relative to a valve seat. A spring is used to bias the armature in an open or closed position, thereby permitting or blocking fluid flow through the valve, respectively. A coil assembly is provided about the sleeve. When the valve is energized, an electromagnetic field or flux generated by the coil assembly slides the armature from the biased open or closed position to a closed or open position, respectively.
Control valves mounted in a HCU are actuated by an electronic control module to provide desired braking functions such as anti-lock braking, traction control, and vehicle stability control.
This invention relates to control valves mounted in a hydraulic control unit of a vehicular brake system. Each control valve includes a single piece sleeve that receives a reciprocating armature. The sleeve includes a reduced thickness section that produces a desirable effect when a control valve is energized. The sleeve also includes a bendable portion that is crimped onto a valve seat to improve assembly of the control valve.
In a preferred embodiment, a hydraulic control unit of a vehicular brake system includes a housing. A bore is formed in the housing. A valve seat is received in the bore. A sleeve is mounted on the valve seat. The sleeve includes an annular groove for receiving material from the housing to retain the sleeve on the housing. An armature core is slidably received in the sleeve.
Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.